A similar pulse motor with four poles is known, for example, from DE 23 60 370 A1. If the rotor of this motor is not in the same position as it was at the beginning of a motor pulse, the rotor starts to move in the direction opposite to the intended one and then maintains this direction of rotation.
Japanese Patent No. 54/8815 and DE 30 26 004 A1 describe pulse motors with radially magnetized rotors and three stator poles.
Described in the magazine "Elektronik" from 1974, Issue 6, page 193, is a pulse motor with two directions of rotation which is provided with two stators, each of which has two pole shoes. Since the stators cross each other in this motor, this results in a relatively great, and thus disadvantageous height.
The present invention is based primarily on the objective of designing an electromagnetic pulse motor in such a way that it has the flattest construction possible and is also very economical to produce.
Such preferably flat pulse motors are required, for example, for clock technology, in particular for analog radio clocks, whereby the pulse motor moves the hands by way of a gear chain. According to another requirement, the hands must also be adjustable with a high adjusting speed. This high adjusting speed can be achieved with two-phased pulse motors of the mentioned type.
Such pulse motors are also necessary for analog motor vehicle display instruments in which digital measuring values must be converted into analog displays.
For analog displays of vehicle driving states, the pulse motor must have extremely good synchronization characteristics and ensure a jerk-free rotation. These characteristics are only realized if the step angles are very small and are of equal size for one rotor revolution. Another important requirement is that no dwelling or stopping moments act on the rotor inside the stator poles when the coils are unpowered. If these requirements are not met, the rotor performs a swinging movement after passing through one step angle, whereby this swinging movement manifests itself in the display instruments as a trembling of the hand that is perceptible to the human eye. This trembling of the hand also occurs when the reduction gear between rotor and hand per se permits minimal step angles of the hands.